Probability? Get off my doorstep.

I had an unusual experience last week here at Mission Control in Darkest France. I was door-stepped by Evangelists. We don’t see too many of those round here. They were working a nice formula; he was older and avuncular, she was young and very attractive. She was chosen to hook the guys, he because he was not threatening to women.

Having the kind of debate one has with Evangelists is a little harder in French than it is in English, at least for me, but I think I did OK. She seemed to like the bit about stardust…it’s nice and romantic.

He, however, brought up the ‘statistical probability of Earth being where it is etc etc’ canard. This is meant to show that the probability of Earth’s existence is so low that there must be magic, or as they would prefer, Divine Intervention, involved. Richard Dawkins debunks this in ‘The Greatest Show on Earth’ very nicely and I recommend it.

It’s a bogus argument because it proceeds in the wrong direction: we are already here. There is no probability about it. The actual probability of the Earth being where it is, is 1:1 or 100% because that is where it actually is.

But this got me to thinking and I did a little thought exercise. What would the probability of any one of us being born when and where we were?

Ali addresses a slightly less extreme calculation by removing the specific location and time of birth, but it still works. It’s definitely worth a read and he also put up an excellent graphic which shows exactly what the odds are, and his method but here’s what he says in his own words:

‘Probability of your existing at all: 1 in 10 to the power 2,685,000

As a comparison, the number of atoms in the body of an average male (80kg, 175 lb) is 10 to the power 27. The number of atoms making up the earth is about 10 to the power 50. The number of atoms in the known universe is estimated at 10 to the power 80.

So what’s the probability of your existing? It’s the probability of 2 million people getting together – about the population of San Diego – each to play a game of dice with trillion-sided dice. They each roll the dice, and they all come up the exact same number – say, 550,343,279,001.’

(The exercise was based on the US population, but even if we used a global sample the figures would hardly change.)

If the probability of any individual human existing is 1 in 10 to the power 2,685,000 then statistically it is impossible for you to exist at all, in practical terms.

But this is a parlour game and that is exactly what the ‘statistical probability of Earth being where it is’ is too. The statistics say it’s impossible, and yet, here she jolly well is, and here we jolly well are too.

The point of this is to show that the logic being used is a nonsense. We are here, all of us. We are not a theoretical future being. The Earth is here and we are on it and we observe the universe from it. Using parlour games like this to show that this implies the existence of a ‘God’ is beyond risible. It’s right through the Tunnel of Stupid and out the other side into the Lake of Total Idiocy.

For the Anti-Apologist, it’s an amusing way to shoot down some of the more scientific-sounding Evangelists. However there are religionards who actually think that ‘God’ really does choose who shags whom and which sperm meets which egg. The Micro-Manager God, we might call this one. Definitely a deity with severe OCD.

The solution is simple: since we are now in the realm of statistics, what is the probability that an invisible man in the sky is hand (or Noodly Appendage) selecting every single sperm from every single ejaculation (including the moon-shots) and deciding which one will enter a specific vagina at the exact right moment and fertilise a particular ovum?

Well there you have it again — that is, by Ali’s method, 1 in 10 to the power 2,685,000.

So in other words, statistically, there is 33,562 times less chance of God doing that than there are atoms in the known universe.